/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.ambari.server.topology.addservice;

import java.util.Map;
import java.util.Set;

/**
 * A strategy that chooses another strategy based on cluster size.
 */
public class AutoHostgroupStrategy implements HostGroupStrategy {

  private final int largeClusterThreshold;

  public AutoHostgroupStrategy() {
    this(10);
  }

  public AutoHostgroupStrategy(int largeClusterThreshold) {
    this.largeClusterThreshold = largeClusterThreshold;
  }

  @Override
  public Map<String, Set<String>> calculateHostGroups(Map<String, Set<String>> hostComponentMap) {
    HostGroupStrategy strategy =
      hostComponentMap.size() <= largeClusterThreshold ? new HostGroupForEachHostStrategy() : new GroupByComponentsStrategy();
    return strategy.calculateHostGroups(hostComponentMap);
  }

  public int getLargeClusterThreshold() {
    return largeClusterThreshold;
  }
}
